Artificial joint preserving tendon and/or sesamoid bone structure

Abstract

An artificial toe joint utilizes a ball in socket joint structure and arms or side walls which are exterior to the bone, the side walls extending around depressions in the metatarsal bone or phalangeal bone, respectively so as to not interfere with sesamoid bones or the attachment of tendons. The resulting joint provides improved strength and durability, and may be used to repair joints which are not suitable for installation of a prior art artificial joint.

1 . An artificial joint comprising:
 a first artificial joint member having a first side and a second side and a support member extending from the second side;   a second artificial joint member having a first side and a second side and a support member extending from the second side; and   wherein the first side of the first artificial joint member and the first side of the second artificial joint member comprise structures which engage one another to form a movable joint;   wherein the support member of the first artificial joint member extends away from the joint along the outside surface of bone when installed.   
     
     
         2 . The artificial joint of  claim 1 , further comprising a metatarsal bone having an end and depressions adjacent the end for receiving sesamoid bones and wherein the first artificial joint member is attached to cover the end of the metatarsal bone without extending into the depressions. 
     
     
         3 . The artificial joint of  claim 2 , wherein the second artificial joint is attached to a phalangeal bone having an end, the phalangeal bone having a tendon of the flexor hallucis brevis attached thereto, and wherein the second artificial joint is attached so as to cover the end of the phalangeal bone without interfering with the attachment of the tendon to the phalangeal bone. 
     
     
         4 . The artificial joint of  claim 1 , wherein the first artificial joint member has a side wall which is formed to wrap substantially around depressions within a metatarsal bone when installed. 
     
     
         5 . The artificial joint of  claim 1 , wherein the first artificial joint member has a side wall which does not extend within depressions within a metatarsal bone when installed. 
     
     
         6 . The artificial joint of claim  55 , wherein the support member is a collar. 
     
     
         7 . The artificial joint of  claim 6 , wherein the collar has an opening positioned around the depressions within the metatarsal bone. 
     
     
         8 . The artificial joint of  claim 5 , wherein the support member is an arm. 
     
     
         9 . The artificial joint of  claim 8 , wherein the arm is opposite the side wall. 
     
     
         10 . The artificial joint of  claim 1 , wherein the second artificial joint member further comprises a second support member. 
     
     
         11 . A method for forming an artificial toe joint comprising:
 selecting a first artificial joint member and attaching the first artificial joint member to an end of a metatarsal bone adjacent a phalangeal bone, the metatarsal bone having depressions formed therein for receiving sesamoid bones, wherein the first artificial joint member is positioned to cover an end of the metatarsal bone and form a generally convex joint surface without interfering with sesamoid bones received in depressions in the metatarsal bone.   
     
     
         12 . The method according to  claim 11 , wherein the method comprises selecting an artificial metatarsal joint member having a first side for forming the generally convex joint surface and a support member extending away from the generally convex joint surface and attaching the support member to the exterior of the bone remote from the end of the bone. 
     
     
         13 . The method according to  claim 11 , further comprising a second artificial joint member attached to an end of a phalange bone adjacent the artificial joint member attached to the metatarsal bone, the second artificial joint member covering an end of the phalangeal bone without interfering with attachment of a tendon of the flexor hallucis brevis to the phalangeal bone. 
     
     
         14 . The method according to  claim 13 , wherein the second artificial joint member has a support arm extending away from the metatarsal artificial joint member which is attached to the exterior of the phalangeal bone distal from the end of the phalangeal bone. 
     
     
         15 . The method according to  claim 13 , further comprising disposing an insert disposed in the second artificial joint member so as to receive the metatarsal artificial joint member. 
     
     
         16 . The method according to  claim 15 , wherein the method comprising selecting an insert having a desired thickness to adjust the length of the toe to a desired length. 
     
     
         17 . The method according to  claim 15 , wherein the method comprising selecting an insert having a concave portion at a desired location of the insert so as to correct an angular orientation between the metatarsal bone and the phalangeal bone. 
     
     
         18 . The method of  claim 13 , wherein the method comprises shaping the end of the phalangeal bone with a generally circular saw blade having a cut-out formed therein so as to reshape a portion of the end without cutting into bone structure attached to a tendon of the flexor hallucis brevis. 
     
     
         19 . The method of  claim 11 , wherein the method comprises shaping the end of the metatarsal bone with a generally circular saw blade having a cut-out formed therein so as to reshape a portion of the end without cutting into bone structure adjacent the depressions in the metatarsal bone which receive sesamoid bones. 
     
     
         20 . An artificial toe joint comprising:
 a first artificial joint member further comprising a top side, lateral sides and a bottom side, a support member extending from a periphery of at least one of the top and sides, the support member being configured for attachment to the exterior of a bone; a first side of the artificial joint member being generally convex and a second side being generally concave so as to receive and cover an end of a bone, the bottom side of the artificial joint member having a nook formed therein shaped to receive a tendon passing along the bone.   
     
     
         21 . The artificial toe joint of  claim 20 , further comprising a second artificial joint member configured with a complementary surface to the first artificial metatarsal joint member, the second artificial joint member further comprising a support member extending from a periphery of the second artificial joint member for attachment to the exterior of the bone. 
     
     
         22 . The artificial toe joint of  claim 21 , wherein the second artificial joint member further comprises an insert removably attached to the remainder of the second artificial joint member, the insert having a generally concave surface for receiving the first artificial joint member. 
     
     
         23 . The artificial toe joint of  claim 20 , further comprising an insert placed between the artificial metatarsal joint member and the artificial phalange joint member. 
     
     
         24 . An artificial joint comprising:
 a first artificial joint member having a generally concave recess for receiving an end portion of a bone, and at least one appendage extending from a periphery about the recess rearwardly so as to engage an outside surface of a bone, the first artificial joint member having a convex surface extending on a side opposite the at least one appendage for engaging a second artificial joint member;   a second artificial joint member having a generally concave recess for receiving an end portion of a second bone, and at least one appendage extending from a periphery about the recess so as to engage an outside surface of a bone, the second artificial joint member having a second recess opposite the first recess for general alignment with the convex surface of the first artificial joint member.   
     
     
         25 . The artificial joint of  claim 24 , wherein the joint further comprises a removable insert disposed in the second recess of the second artificial joint member, the removable insert having a concave surface for receiving the convex surface of the first artificial joint member. 
     
     
         26 . The artificial joint of  claim 25 , wherein the first artificial joint member and the second artificial joint member are aligned such that the at least one appendage of each artificial joint member extend generally opposite one another. 
     
     
         27 . The artificial joint member of  claim 24 , wherein the at least one appendage of the first artificial joint member comprises at least one arm. 
     
     
         28 . The artificial joint member of  claim 24 , wherein the at least one appendage of the first artificial joint member comprises a collar. 
     
     
         29 . The artificial joint member of  claim 24 , wherein the at least one appendage of the second artificial joint member comprises at least one arm. 
     
     
         30 . The artificial joint member of  claim 26 , wherein the at least one appendage of the second artificial joint member comprises a collar.